Atherosclerosis disease of the carotid is one of the major reasons for stroke. An accurate diagnosis and severity quantification of the disease is therefore needed to prevent symptoms and decide the appropriate treatment. The most important indicator for the risk of symptoms is the Degree of Stenosis (DS). Very recently, a new score was proposed, called Enhanced Activity Index (EAI), which is more complex but more accurate than DS. EAI, however, only takes into account medical information about the patient. The optimal EAI cut-off for endarterectomy is computed under the Receiver...